Electric heater.



W. S. HADAWAY, Jn.

ELECTRIC HEATER.

APPLIOATION FILED EEB, 20, 1913. 1,099, 1 25. Patented Jung 2, 1914.

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Arrofmfy ovm UNrrED Asfrrrrns 'PATENT OFFICE.

A WILLIAM S. HADAWAY, JR., F NEW ROCHELLE, NEW YORK.V

ELECTRIC HEATER.

Specification of Letters Patent.

Patented 'June l2, 1914.

My invention relates to electric heating apparatus.

' One of its objects is to provide a compact and durable heater structure that shall be relativelyv simple and inexpensive to manufacture and shall embody a fluid containing tube or equivalent means for transferring heat to the active portion of the structure and distributing heat therein.

Other objects of my invention will. be set forth hereinafter.

In my copending application Serial Number 749,595 tiled of even date herewith, I have shown and described a heaterl and regulator system embodying electric heating apparatus having the same characteristics as that of my present invent-ion. I claim as my present invention however, the preferred heater structure per se.

307 Referring to the drawings, Figure lis a plan view of a heater constructed in accorda-nce withmy invention. Figs. 2 and 3 are sectional elevations at right angles to each other of the structure of Fig. 1. Figs.

'4 and 5 are views corresponding to Figs. 2 and 3 of a modified structure embodying my invention. Another modification of my invention is shown in Fig. 6 which is a view7 corresponding to 'F igs. 3 and d. A`portion of one of the`heater units ig shown on a.

larger scale in Fig. 7 the insulation being broken away to disclose the resistance element. Fig. S is a transverse sectional view i of the heater unit of Fig'. 7.

Like characters of reference designate corresponding parts in all the figures.

The heater shown in Figs. 1 to 5 inelusive`is adapted for use as a bed or pressure plate of a matrix drying press but it may of course 'be utilized for various purposes. It comprises a body 10 having a plurality of substantially parallel grooves or chair nels 11,a cover plate 12 which is secured to the body 1() by bolts 13, and end plates 14 .and 15. In the channels 11 are disposed a plurality of liattened tube sections 16 which are units 18.

The electric heater units may 'be of any suitable structure but I prefer to employ flat metalclad units such as-that shown in Figs. 7 and 8. This unit comprises a resistance ribbon 19, having transverse slots 20 eut alternately from opposite edges of the ribbon to provide a relatively long zigzag path for the electric current, insulating strips'2l, placed one ,onl each side of the ribbon, and a sheet metal sheath composed of a channel 22 into 'which the insulated heater ribbon is placed, and a metal strip 23 over which the edges of the channel are folded.

For economy ofspace and eiicieney in operation the flattened tubes and the heater units are preferably made'the same size in 75 transverse section and fit closely into the channels 11 in the body of the heater. In the structure illustrated, 25 is the working sui-face of the heater and flattened tubes 16 are placed in the'bottoms of the respective 80 channels so that they are adjacent to the working surface, The flattened tube sections are preferably closed at onev end as shown at 26 and the other Vend extends through the end plate 15 which is perfo- 35 rated for this purpose. The tubes are sealed into a header27, which establishes a communication between them. The header is provided with end caps 2S, and two pipes 29' and 30 lead outwardly from it. Io

The tube system composed of the header and flattened tubes is preferably filled with water as hereinafter pointed out and is a closed system to which water is only supplied to compensate for leakage. The pipes g5 29 and 30 are adapted to be connected to external, thermometer or regulating apparatus but do not constitute outlets, the water and steam being confined within the system. In fact, the pipes 29 and 30 may be omitted entirely.

In operation, assuming that electric c urrent is supplied to the heater units which may be connected in any suitable relation and supplied from any suitable source of energy (not shown), the heat will be rapidly transferred from the units to the adjacent liquid containing tubes and the temperature of the fluid and the pressureof the tube system will be proportionately increased. y

Inaslnuch as the tube sections are all inspaced apart by electric heater terconnected there Will be such a circulation of the fluid' as to tend to uniformly distribute the heat throughout the entire body of the heater, irrespective of the location and distribution of the heater units, provided the heater units are in close engagement With the fluid containing tubes. The closed tube system may be utilized for various purposes such', for example, as indicating the integrated temperature of the heater body and governing the supply of energy to the heater units as set forth in my co-pending application Serial Number 749,595 to Which reference has already been made.

In some cases it is particularly desirable to protect the Working surface of the heater against the possibility of excessive temperatures and While the closed Huid pressure tube system, shown in Figs. 1 to 3 inclusive,

tends to distribute the heat in such a vvayA that excessive temperatures are avoided, there is of course a' possibility (although it is very remote) that the Water may be accidentally exhausted from the system. In this case the temperature of the Working surface may increase to an abnormal degree and the body, such as a matrix, to which heat is being imparted, may be damaged.

The structures shown in Figs. 4, 5 and 6, to which special reference may now be had, are intended to limit the temperature of the wor-king surface to a safe value even under such abnormal conditions as those above described. The structure of Figs. 4 and 5 comprises a member which is similar in construction to the entire heater of Figs. 1, 2 and 3, and a member 40 which is separated vfrom the member 35 by a member 41 of heat insulating material. The Working surface 25 of this heater is a part of the member 40 which is relatively thin and is provided with a single set of tube sections 16 and heater unitsv 18. These tube sections are sealed into a header 27A.

l The member 35 is provided With a relatively large number of tube sections and heater units arranged as in the structure of Fig. 3 and these tube sections are sealed into a corresponding header 27. The heater units of this member are therefore capable of generating a relatively large quantity of heat; The headers 27 and 27A4 are interconnected'by removable pipe connectors 42 only one of which is shown.

' The heater units 18 of the section 40 ob-k units 18 of lthe member' 35 under such abnormal conditions. When the structure is operating properly however, the tube sectlons and headers are filled with Water as in the structure already describedand the heat produced in all the heaters is distributed With approximate uniformity throughout the entire mass of the heater and the Working surface is thus provided With heat- Iof a predetermined intensity. In fact the heater units may be entirely omitted from the section having the Working surface 25 and all of the heater units located in the other member which is separated from it by insulating. This latter arrangement is shown in Fig. 6.

Variations in size and arrangement of parts may of course be effected within the spirit and scope of my invention.

What I claim is:

1.l An electric heater comprising a solid body of heat conducting material having a plurality of channels, a normally closed. fluid containing tube disposed in the body, and electric heater elements disposed in the c nels for supplying heat to the duid con .aining tube and to the body.

2. An electric heater comprisi. body of heat-conducting material plurality of substantially parallel channels, a normally closed fluid containirn ubs disposed in the channels and distributed through the body and electric heater elements disposed in the channels, adjacent to the tube.

3. An electric heater comprising a solid body of heat conducting material having Working surface and a plurality of sub-stantially parallel and relatively d ep channels, flattened tube sections, adapted to contain lvvater, disposed in said channels and flatu tened metal clad heater elements in the channels adjacent to the flattened tube sections.

4. An'felectrie 'heater compri solid body of heat conducting material having a Working surface, and a plurality' of grooves or channels, flattened tube sections, adapted to contain Water., disposed in said channels and heater elements disposed in channels between the iiattened tube sections.

the tions, and means for establishing communication bet-Ween the tube sections. y

6. An electric heater comprising rectangular metal body having a plane Working surface and a plurality of substantially arellel channels opening on the opposite side of the body from the Wertung surface,

disposed and being deep relative to the thickness of the body, flattened tube sections, adapted to be filled with water, disposed in said channels, flattened heater units disposed in said channels between the flattened tubesections and a'header for establishing communication between the tube sections.

7. An electric heater comprising a solid body having two hea-t conducting members,

separated by a heat insulating member, electric heater elements disposed in one of the heat conducting members and intercommunicating fluid containing tube members disposed in the respective heat conducting members 8. .An electric heater comprising a solid body having two heat conducting members, separated by a heat insulating member, electric heater elements disposed lin the heat conductingmembers and unequally divided between them and intercommunicating fluid containing tube members disposed in the respective heat conducting members.

9. A11 electric heater comprising a solid bodyT having two heat conducting members and an interposed heat insulating member, a plurality of flattened tube sections disposed in the two heat conducting members, a header arranged to interconnect the tube sections of one member, another header arranged to interconnect the tube sections of the other member, and electric heater units associated' with the flattened tube sections.

l0. An electric heater 4cmnprsing a solid body having two heat conducting members and an interposed heat insulating' member, a plurality of flattened tube sections disposed in the two heat conducting members, a neader arranged to interconnect the vtube sections of one member, another header arranged to interconnect the tube sections of the other member, and electric heater units associated with the flattened tube sections,

and removable means for joining the headers.

1l. An electric heater comprising a solid body having two heat conducting -members,

separated by a heat insulating member, electric heater elements disposed in the heat c onducting members and divided between themand intercommunicating fluid containing tube members disposed in the respective heat conducting members.

12. An electric heater comprising a solid body having two heat conducting members and an interposed heat insulating member, a plurality of flattened tube sections disposed in' the two heat conducting members, a header arranged to interconnect the tube sections of one member, another header; arranged to interconnect the tube sections of the other member, and electric heater units associated with the flattened tube sections.

13. An electric heater comprising a solid body having two heat conducting members and an interposed heat insulating member, a

plurality of flattened tube sections-disposed inthe two heat conducting members, a header arranged to interconnect the tube sections of one member, another header arranged to interconnect the tube sections of the other member, and electric heater units associated .with the flattened tube sections, and removable means for joining the headers.

In witness whereof, I have hereunto set` my hand this 17 day of February in the year WILLIAM S. HADAVAY. JR. l/Vjtnesses R. J. DnAnBonN, F. GRAVES. 

